In this essay, an attempt is made to interpret the iconographic type of St. Christopher, in the form of a dog, as well as to investigate the causes of the creation of this iconographic type, based on its various biographical data, as reported by various authors. Essentially, an attempt is made to find the iconographic model of this iconography, while at the same time a theological approach is given to the iconography of the saint in the form of a dog. It is a hagiological, iconographic and theological approach to a portable composition of St. Christopher that comes from the Holy Monastery of Serres and Nigrita and dates back to the 19th century.